A semiconductor device may be required to operate at high speed and simultaneously have mass storage capability. Accordingly, a semiconductor device may be manufactured to meet increasing requirements of better operation as well as the need for miniaturization.
A semiconductor device may include transistors, resistors, capacitors, etc. To electrically connect such a semiconductor device, wiring may be necessary. The wiring of a semiconductor device may have low resistance, may be economical, and may have high reliability. In a highly integrated semiconductor device, a width and thickness of the wiring may be reduced. Therefore, it may become a more difficult to form the wiring.
A metal used to form semiconductor wiring may primarily be fabricated of copper or aluminum. When made from copper, wiring may be formed through a damascene method. In this process, a trench may be formed in an insulation layer, and the trench may be filled with the copper. When made from aluminum, semiconductor wiring may be formed by forming an aluminum layer on an insulation layer, and selectively etching the aluminum layer. In this case, it may be possible to more easily form patterns than when using copper.
Aluminum wiring may be etched, for example by using etching gas such as CHF3 and N2. However, when using such a gas, a photo resist layer may also be etched when a metal layer is etched. Since the amount of the photo resist layer etched increases as the etching time of the metal layer increases, a thickness of the photo resist layer directly corresponds to the thickness of the metal layer.
According to the related art, since photoresist layer pattern (PR) may also be removed during an etching of conductive layer 104a, photoresist layer pattern (PR) may be thickly formed.
The etched photo resist layer may remain as polymers within an etching chamber instead of being volatilized. As a thickness of the photo resist layer increases, the amount of remaining polymers may also increase. Thus a cleaning cycle of the etching chamber may become shorter. The etching chamber may have a cycle of 10,000.
In addition, the gas used for the etching may cause particles by reacting with the photo resist layer and the metal layer. Such particles may be particles against etching, for example such as Al(CF)x and AlFx including Carbon (C). These particles may deteriorate a uniformity of etching, and may cause the short-circuiting of metal wiring within the semiconductor device.